I believe this is already the case. One is supposed to look for prior art. In fact, most patents build on something else and do list prior art.

The problem with proving something is an exact copy is just the nature of our field - anything can be argued as a copy or innovation.

Most ideas that get patented are reasonable next steps from an existing idea anybody in the profession with half a brain will take.

Slight correction on your first point.

There is no requirement that one looks for prior art. 37 CFR 1.56 requires that an applicant disclose pertinent prior art that is already known to the applicant or his lawyer and disclose prior art that the applicant becomes aware of during the application process.

> In nonprovisional applications, applicants and other individuals substantively involved with the preparation and/or prosecution of the application have a duty to submit to the Office information which is material to patentability as defined in 37 CFR 1.56.

See https://www.uspto.gov/web/offices/pac/mpep/s609.html

> but I wonder if USPTO could set up some rules whereby the person asking for a patent has to do some sort of search for prior art, in order to get the patent

Disclosing prior art, and how your patent builds on and is different from it, is part of the patent application process.

> and if they don't or do it badly/ not to the rules, then a penalty is applied

That penalty is the patent is completely invalidated.

In theory, but in practice getting a patent invalided is a fraught and unreliable process. The courts have been generally deferential to the the USPTO decision, which may be a problem if some examiners have allowed patents to go through on the assumption that the courts can fix it later if they get it wrong.